a newspaper conducted a statewide survey concerning a proposal to raise taxes in order to prevent budget cuts to education. the newspaper took a random sample (assume it is an srs) of 1200 registered voters and found that 580 would vote to raise taxes. let p represent the proportion of registered voters in the state that would vote to raise taxes. 21. a 90% confidence interval for p is a. b. c. d. 22. how large a sample n would you need to estimate p with margin of error 0.01 with 95% confidence? use the guess p